Relay contact assembly



Jan. 19, 1965 RELAY CONTACT ASSEMBLY Filed Aug. 21. 1961 I5 Shams-Sheet1 so 6' 0 A INVENTOR.

WILLARD A.ROBERTS FIG. |5b

ATTO RN EYS w. A. ROBERTS 3,166,662,

Jan. 19, 1965 w. A. ROBERTS 3,165,662

RELAY CONTACT ASSEMBLY Filed Aug. 21. 1961 3 Sheets-Sheet 2 FIG. 5

FIGS

INVENTOR.

WILLARD A. ROBERTS ATTORN EYS 1965 w. A. ROBERTS 3,166,662-

RELAY CONTACT ASSEMBLY Filed Aug. 21. 1961 5 Sheets-Sheet 6 FIGH 5OFIG.|2

FIGIE FIG.I4

IN VEN TOR.

WILLARD A. ROBERTS BY ATTOR N EYS United States Patent "ice 3,166,662RELAY CQNTACT ASSEMBLY Willard A. Roberts, Hanover, Mass., assiguor toJoseph Pollah Corp., Dorchester, Mass, a corporation of MassachusettsFiled Aug. 21, 1961, Ser. No. 132,819 Claims. (Cl. 200-466) The presentinvention relates to a relay and in particular to a relay adapted foruse with circuits carrying radio frequency and direct current loads.

Relays for use in circuits carrying radio frequency and direct currentloads should be designed to minimize capacitive ettects between therelay components. In addition it is usually desirable that the relay berugged in construction, capable of millions of operations withoutfailure, and also relatively compact. Further, limitations of powerintroduce additional problems into relay designs, particularly those forradio frequency circuitry. Limited power and space problems are furthercomplicated when multiple terminal relays are desired.

The present invention is designed to overcome such problems by providinga relay in which capacitive effects are minimized by widely spacing thecontacts and by reducing their size. In addition power requirements areminimized by utilizing a unique movable contact for electricalinterengagement of a plurality of fixed contacts with equalsimultaneously applied forces from selected angular directions.

In the arrangement of the present invention, designed particularly forcircuits carrying radio frequency and direct current loads, a pair offixed contacts are secured with areas lying in a common plane. A movablecontact is formed with a pair of electrically conductive portions lyingrespectively in planes defining an angle of 120 therebetween. Theseportions are arranged symmetrically and equidistant from a common centerwith the portions and common center lying substantially normal to theplane in which the fixed contacts lie. These conductive portions aresupported by an elongated member extending preferably from the commoncenter.

In a preferred embodiment of the invention the movable contact is formedof an elongated wire having a portion of its length extending in onedirection and terminating in a ring with the aforementioned portion ofwire extending normally from the ring. The radius of the ring is equalto equal radii from a common center to the pair of fixed terminals whichradii include an angle of 120. The movable contact is adapted to bemoved so that it moves in a plane symmetrical with respect to the fixedcontacts. Thus the electrically conductive portions of the movablecontact simultaneously engage the fixed contacts with equal forceapplied in two directions 120 apart.

These and other objects and advantages of the present invention will bemore clearly understood when considered in conjunction with theaccompanying drawings in which:

FIG. 1 is a side elevation of a relay embodying my invention;

FIG. 2 is a top plan view of the relay illustrated in FIG. 1;

FIG. 3 is a front elevation of the relay illustrated in FIG. 1;

FIG. 4 is a bottom view of the relay illustrated in FIG. 1;

Each of FIGS. 5a to 14a inclusive; 5b to 14b inclusive; and 50 to 140inclusive; are respectively; top plan fragmentary views of modificationsof the contacts; front elevations of the correspondingly bracketed topplan views; and schematics of the correspondingly bracket modifications;

3,156,662 Patented .Ian. 19, 1965 FIG. 15a is a front elevation of afurther modification, and 15b is a schematic circuit of the modificationillustrated in 15a.

A preferred form of the present invention is illustrated in FIGS. 1 to4. In this arrangement a bobbin Wound coil 1 is supported on an L-shapedsupporting bracket 2 having a base 3 and rear leg 4-. The coil issuitably insulated from the bracket at its lower end by dielectric sheet5' and at its upper end is secured to a dielectric sheet 6 with the core7 projecting slightly upwardly through the sheet 6. Terminals 9 and 16are secured by suitable means to the lower surface of the dielectricsheet 6 and project forwardly from it preferably with a stepped section.These terminals are connected to the relay coil 1 for purposes ofsupplying power to it. A ground contact 11 is riveted or otherwisesuitably secured to the base 3.

The relay armature comprises a conductive flat plate 14 positioned witha portion directly above the core 7. The rear portion 15 of this plateis formed with six bosses 16 on its lower surface. These bosses aresymmetrically and triangularly arranged in two groups of three with agroup at each side edge of the rear leg 4 of the L-shaped bracket. Thesebosses form means for loosely and pivotally interengaging the armature14 with the rear leg 4 while limiting relative lateral movement. Oneboss at each end engages the forward surface of the rear leg in an areawhich projects just above the dielectric sheet 6, a second boss at eachend engages the rear surface, and a third boss engages the side edges atthe upper end of the rear leg 4.

A helical spring 17 is formed with engaging hooks 1S and 19 at eitherend. Hook 19 is secured to a tab 20, in turn screwed to the rear surfaceof the rear leg 4 by screw 21. The tab may be rotated and tightened intoa selected position about this screw for purposes of adjusting thetension on the spring 17. The upper hook 18 engages a hole in the rearportion of the armature 14 thereby tensioning the armature to move in adirection away from the core 7. The armature is restrained against thetension of spring 17 by interengagement of the movable contacts 25 andthe fixed contacts generally illustrated at 26. The movable contacts 25which may, for example, comprise three in number, are each formed withan elongated wire portion 27 secured at one end to the rear portion ofthe flat plate 14 by means of dielectric plates 29 and 30 which havesandwiched between them the ends of the wire portion 27. The ends ofportions 27 may also be molded into dielectric material to form theassembly. These dielectric plates 29 and 30 are in turn secured to therear portion of the armature by rivets 31 which project through the ingdielectric bar 36 which is integrally formed with the sheet 6. Thesefixed contacts 26 may be varied in configuration and number but in themodification illustrated in FIGS. 1 to 4 comprise three sets of fourterminals.

The four terminals in each set are arranged in pairs with one pairillustrated at 37 and the other at 38 (FIG. 3). Each terminal is formedas a hook member having a shank 39 projecting through the bar 36 withthe forward portion formed as a hook 40. The hooks 40 of the terminalpairs 37 project upwardly while the hooks 40 of the terminal pairs 38project downwardly. The rear ends 41 of the pairs 37 are positionedabove the ring or disc 33, while the rear ends 4-2 of the terminal pairs33 are positioned below the ring or discs 33, so that the ring or discs33 are limited in movement between the rear ends 41, 42.

of upper and lower terminal pairs 37 and 38 respectively.

The specific arrangement of the movable contact and fixed terminals 37and 38 of the preferred embodiment illustrated in FIGS. 1 to 4 is shownin greater detail which define an angle of 120 and terminate at theirends at the ends 41 of terminals 37. Terminal ends 42 are spaced apartthe same distance as terminal ends 41. The elongated portion 27 isadapted to be moved on movement of the armature 14 in a plane normal tothe aforementioned common plane so that simultaneous contact is madebetween the periphery of the rings 33 and each of the terminal ends 41on de-energization of the coil, and upon energization of the coilsimultaneous engagement is made with each of the terminal ends 42 toactuate an electrical circuit as illustrated in FIG. 5c. The arrangementillustrated provides contact pressures at the terminal ends 41 eachequalto the total force delivered by the movable contacts 25. With 30 gramsforce exerted vertieally at the center of the ring and contact terminalends 41 arranged to contact points on the ring 120 apart, a force of 30grams is thereby impressed upon each of the terminal ends 41. If theangle were increased from 120 the force applied to the terminal ends 41would also increase but the rate of opening between the terminal endsand rings and the contact gap for a given ring movement would decrease.The converse would happen if the angle was decreased. A similar actiontakes place at terminal ends 42. Such arrangement eliminates criticaladjustments and reduces the force required to complete the circuit. Sucharrangement also permits selective contact arrangements for specificapplications. The configuration illustrated in FIGS. 5a to 5c is adouble make or double break type of circuit.

The configuration illustrated in FIGS. 6a, 6b, 60 to 14a, 14b, 14cillustrate corresponding modifications of the terminalarrangementillustrated in FIGS. 5a, 5b, 50. In FIG. 6 there is illustrated a doublecontact in which terminal 41 is formed to provide two common points forengagement with 33 and terminalends 42 are common; The movable contact25 is flexible wired to terminal A to provide a fixed terminal for themovable contact 25. Further, the elongated portion 27 is aligned withthe radial center of the ring 33. FIG. 7 illustrates a double breakcontact in which a solid disc 46 is substituted for the ring 33illustrated in FIGS. 5a and 5b. FIG. 8 illustrates a double make doublebreak arrangement in which a solid disc 46 is secured to a fiat blade 47by welding or other suitable means, with the flat blade terminating atits end remote from the disc 46 in a support similar to the support formovable contact 25. FIG. 9 illustrates a configuration similar to thatof FIG. 6 except for the substitution of a movable contact assembly 25of the type illustrated in FIG. 7. FIG. 10 illustrates a modificationsimilar to FIG. 6 but having a movable contact assembly similar to thatof FIG. 8. FIG. 11 illustrates an arrangement in which the upperterminal ends 41 are common as are the lower terminal ends 42. Themovable contact assembly 25 having ring 33 is connected to an auxiliaryterminal 50 by wire 51. FIG. 12 illustrates an arrangement similar tothat illustrated in FIG. 11 except that upper terminal ends 41 and lowerterminal ends 42 are not common but are each independent of the other.FIG. 13 illustrates an embodiment in which one upper terminal end 41 andone lower terminal end 42 are common. FIG. 14 illustrates an arrangementsimilar to that illustrated in FIG. 5 except that the ring 33 is formedwith a plurality of convolutions 55. This arrange- 4 ment assures a morecertain contact. FIG. 15 illustrates a modification in which three setsof movable contacts 25 are provided with rings 33 adapted to move intoand out of contact with terminals 60, d1, 62 and 63, with terminals 6t?and 61 connected and 62 and 63 connected when the relay is de-encrgizedand terminals 61 and 62 connected with the relay is energized.

. What is claimed is:

1. In a relay construction for use in radio frequency circuits, a pairof fixed contacts, means mounting said contacts in a common plane, meansforming a movable contact adapted to electrically interconnect saidfixed contacts including an arcuate surface means having a radius equalin length to each of a pair of lines of equal length defining an angleof with the lines of equal length extending from a common center andterminating at the ends of said fixed contacts, and means mounting saidmovable contact for movement of said surface means in a direction normalto said common plane and symmetrical with respect to said fixed contactswhereby said surface means will simultaneously contact said fixedcontacts with equal force.

2. A relay as set forth in claim 1 wherein said movable contact andsurface means are formed by a length of wire with one end of the wireformed substantially as a ring in a plane normal to said direction.

3. A relay as set forth in claim 1 wherein said movable contact andsurface means are formed by a length of wire extending in one directionwith one end of the wire coiled substantially into a ring having atleast one convolution lying in planes normal to said one direction.

4. A relay as set forth in claim 1 wherein said movable contact andsurface means are formed by a length of wire extending in one direction,a conductive disc having a radius equal to said equal radii secured atits center in a plane normal to and to one end of said wire.

5. In a relay construction for use in radio frequency circuits, a pairof fixed contacts having portions lying in a common plane, means forelectrically interengaging said contacts comprising electricallyconductive means having a pair of areas that pass through a pair ofplanes defining an angle of 120 therebetween, said areas arrangedsymmetricaily and equidistant from a common center in the line ofintersection of said planes, means for moving said areas in a planesubstantially normal to said common plane and symmetrical with respectto said portions, whereby said areas may simultaneously make and breakcontacts with said portions.

6. In a relay construction for use in electrical circuits, a pair offixed contacts having portions lying in a common plane, means forelectrically interengaging said contacts comprising electricallyconductive means having a length of wire extending in one direction withone end of the wire coiled substantially into a ring with said ringlying in a plane normal to said one direction, means for applying aselected force to said electrically conductive means with said ringadapted to engage each of said fixed contacts with a force equal to saidselected force.

7. A device as set forth in claim 6 wherein said end of said wire iscoiled into a ring having a plurality of convolutions each having areasadapted to simultaneously engage said fixed contacts.

ductive means having a length of wire extending in one direction, aconductive disc lying in a plane normal to sa1d one direction alignedwith said common center; said disc having peripheral surface areasadapted to be simultaneously engaged with said fixed contact portions.

9. In a relay construction fixed contact means having upper and lowerpairs of terminals, means fixedly supporting said terminal pairs inparallel planes, a movable contact means adapted to be moved between andthereby References fited by the Examiner alternately interengage theterminals of said upper and UNITED STATES PATENTS then said lower pairs,said movable contact means comprising means having arcuate sectors atits periphery each 1068945 7/13 Taylor 200-82 n 2,251,648 8/41 Wayman20O 82 adapted to mterengage the terminals of 831d pairs, 831d 5 66arcuate sectors each having a radius equal in length to 2,541,398 2/51Wood 200 1 7 equal each of a pair of lines of equal length emanating2677024 4/54 Welch ZOO-8 from a common center that define an angle of120 and 2,931,877 4/60 200-166 2,932,704 4/60 Dennlson et a1. 200-87terminate at ad acent termlnals of a pair. 2 965 739 12/60 Al d 200 110. A device as set forth in claim 9 wherein said arcuate 10 exan ersson1 sectors are portions of a ring, BERNARD A. 'GILHEANY, PrimaryExaminer.

MAX L. LEVY, Examiner.

5. IN A RELAY CONSTRUCTION FOR USE IN RADIO FREQUENCY CIRCUITS, A PAIROF FIXED CONTACTS HAVING PORTIONS LYING IN A COMMON PLANE, MEANS FORELECTRICAL INTERENGAGING SAID CONTACTS COMPRISING ELECTRICALLYCONDUCTIVE MEANS HAVING A PAIR OF AREAS THAT PASS THROUGH A PAIR OFPLANES DEFINING AN ANGLE OF 120* THEREBETWEEN, SAID AREAS ARRANGEDSYMMETRICALLY AND EQUIDISTANT FROM A COMMON CENTER IN THE LINE OFINTERSECTION OF SAID PLANES, MEANS FOR MOVING SAID AREAS IN A PLANESUBSTANTIALLY NORMAL TO SAID COMMON PLANE AND SYMMETRICAL WITH RESPECTTO SAID PORTIONS, WHEREBY SAID AREA MAY SIMULTANEOUSLY MAKE AND BREAKCONTACTS WITH SAID PORTIONS.